Transport aircraft are often large to contain substantial payloads. Parking and stowage of such aircraft on an airport ramp or in a hangar requires a large space that is difficult to obtain in ever more crowded airports. This difficulty is extreme when stowage of military cargo aircraft (or rotorcraft) is required in forward military bases on land or onboard a ship.
It is of military interest to consider the basing of armored vehicles and heavy transport rotorcraft on ships (called seabasing). U.S. utility patent application Ser. No. 12/342,891, filed Dec. 23, 2008, describes such a seabasing ship, which provides for the flight operations of multiple heavy transport rotorcraft. Prior art FIG. 1 depicts tiltrotor aircraft 102, 104 on the deck 140 of a ship 100. Folded aircraft 106, 108 sit on an elevator 142 at the stem of the deck 140. The option of compact folding of such heavy lift rotorcraft aircraft 102, 104 allows two, three, or even more aircraft to be moved on a ship elevator 142 and stowed in a hangar below the flight deck 140.
An exemplary fully folding tiltrotor aircraft is depicted in prior art FIG. 2. The tiltrotor aircraft 200 has a wing 210 positioned above the fuselage 212 that can rotate from a position perpendicular to the fuselage 212 into a position inline with the fuselage 212. The fuselage 212 is supported on landing gear 214. A first tilting rotor 220 remains in a roughly horizontal position over the fuselage 212. Folding blades 222, 224 are coupled to the rotor 220. Some additional portions of the aircraft may also fold or rotate, including an outboard wing 216 or a horizontal or vertical tail (not shown). In general, such rotating or folding joints need to sustain substantial flight loads and tend to significantly increase the aircraft weight and drag. For practical applicability, such joints need to be powered to provide aircraft folding in winds of 60 knots or higher. This requirement tends to add weight and cost to an aircraft design.
The substantial development cost, the increase in aircraft unit cost, as well as the increased aircraft weight and drag associated with a fully folding scheme as depicted in FIG. 2, raises the need for a compact stowage scheme that does not incur the penalties of the fully folding scheme. A low-impact compact stowage scheme is highly desired for stowing a higher number of aircraft on the ship deck than otherwise possible.